Method of forming electric plug connectors



Feb.11 ,1941. RRREUTTER 2,231,347

METHOD OF FORMING ELECTRIC PLUG commcwons Filed Jan. 11," 1958 III INVENTOR Frederick RoReuttev BY Patented Feb. 11, 1941 nm'rnon on some ELECTRIC PLUG conmzcroas Frederick R. Reutter, Waterbury, Coma, assignor to Scovill Manufacturing Company, Waterbury,

Conn., a corporation or Connecticut Application January 11, 1938, Serial No. 184,399 3 Claims. (Ci. 29-15555) This invention relates to contactor prongs for electric plug connectors and particularly to the method of making sucha prong.

The recent trend in the manufactureof this commodity is to make and market a plug connector in which the body part is made of a relatively soft. rubber material which renders the article non-breakable and presents other advantages in the assembly of the unit. It isutherefore, one of the objects of this invention to make I a suitable contactor prong that in being assembled to such a plug connector can be securely anchored therein with the minimum. of effort and expense. l

15 A further object is to make a contactor prong forthe above use in which the original metal stock from which the prong is made is no wider than the finished width of the prong, this resulting in substantial economies in manufacture.

20 The.porti6n of this prong which is embedded into tifi rubber stock isprovided with locking elements which are forced or peened outwardly-from the opposite longitudinal edges of the prong. This is effected by striking a forceful blow near the 25 edge of the prong in such a-manner as to drift or force the metal out of its normal bounds in the form of a relatively sharp barb. When the prongs are inserted into their respective sockets in the plug body, the sharp barbs become em- 30 bedded within the rubber material locking the prongs therein and effectively preventing theirg withdrawal therefrom.

Other objects and advantages of the invention will be apparent from the following description which taken in connection with the accompanying drawing discloses a preferred embodiment thereof.

In the drawing: i

Fig. 1 is a side elevation of a conventional form 40 of electric plug unit of the type in which the invention may be embodied.

Fig. 2 is a vertical section through the same, showing the manner in which the electrical connection is made between the prongs and conductors.

Fig. 3 is a transverse vertical section through the prong member taken on the line 3-3 of Fig. 2. Fig. 4 is a fragmentary vertical section view 50 taken on line 5-5 of Fig. 3.

Fig. 5 is a plan view of the prong member, per se. as it appears before the barb forming operation.

Fig. 61s a perspective view or the contactor 55 prong in its finished state, and

' longitudinal edges.

Fig. 7 is a view similar to Fig. 2 oi the 'body vmember, per se.

In the drawing the numeral 10 designates a. plug body member made of relatively soft rubber material. The inner face end of the body mem- 5 ber is provided with a recess ii connecting with a central orifice i2 passing through the length of the body in, and through which a twin conductor cable i3 may be inserted. Opening into the opposite ends of the recess ll area pair of 10 relatively narrow prong reception sockets I 4, H extending in parallel for a substantial distance into the body Ill. The sockets ll, ll are adapted to receive and retain a pair of electrical terminal or contactor prongs l5, IS in a manner to be later described, the construction of the prongs being'the principal substance of this invention. The twocontactor prongs used in this device are identical and a description of one may stand for both. The manner in which this prong I5 is produced is best illustrated in Figs. 5 and 6. Herein the original blank indicated by the numeral i6 out of which the prong I5 is fabricated is shown in Fig. 5 of a width'the same as the width of the metal stock. The metal stock out of which the blank I6 is out is shown in Fig. 5 in dotted outline and indicated by the letter X.

Adjacent one end of the blank i6, 9. pair of opposed slots l1, l1. are cut in from the opposite Specifically the slots H, i! are cut so that one sheared wall I8 is inclined to the longitudinal axis of the blank 16 while the opposite sheared wall is thereof is disposed substantially perpendicular to the axis of the blank.

In order to produce a suitable means for locking the prongs IS in position within the body It, provision is made of projections on barbs 20 ex- I tending beyond the opposite longitudinal edges. of

the blank i8. These barbs Iii are produced by supporting'the blank l6 upon a suitable anvil and giving the metal stock near the sheared wall It a severe blow with a rounded nose punch and creating a pair of sockets 2i, 2! in the adjacent face of the blank. The concave sockets 2i, 2! formed by the punchcausethe metal so displaced to be drifted or forced to the side, the metal traveling in the direction ofleast resistance, and by reason of the slots ii the metal is virtually peened or extruded outwardly beyond the longitudinal edges of the blank, thus creating the barbs 20 above mentioned. It is to be noted that the leading edges of the barbs 20 forced into the sockets it are disposed at an obtuse angle to the adjacent blank edges,

I consequently permitting relative easy insertion of that end of the contactor prong l into the socket I4. The opposite wall of the barb 20 is disposed at an acute angle to the adjacent edge of the blank l6, which condition disposes the barbs 20 to deeply embed themselves into the rubber material and crowd it into the slots l4, l4

and in consequence to lock said prongs in permanent assembly with'the body more and more securely as pressure is exerted to withdraw the prongs therefrom.

Figs. 3 and 4 show the condition in which the cidentally the sockets 2| form additional recep-.,

tion chambers into which the rubber may be crowded as an added retaining and stabilizing factor. v

The manner in which the assembly is effected is best shown in Figs. 2 and 3. The conductors 23 of the twin cable l3 are stripped of a substantial length of the insulation material at the inner end thereof, the cablefirst being inserted through the 'central orifice l2 of the body l0. Each prong l5 is provided with an intermediate hole 24 and the inner end of the prong is provided with a terminal notch 25. To effect an electric connection between the conductors 23 and prongs i5 that portion of the conductor that is stripped of insulation is inserted from the inner face of the prong l5 through the hole 24. The conductor 23 isthen passed upwardly along the opposite face of the prong and finally bent around the end notch 25 with the end of the conductor 23 resting against the inner face of the prong I5. With the conductor 23 so disposed the prongs l5 are then forcibly inserted into .the sockets l4, the compression of the rubber material of the body naturally causing the strands of the conductor 23 to be firmly pressed against the opposite faces of the prongs to assure a good electrical connection.

-Various modifications will occur to those skilled in the art as to other ways of producing locking means for plug contactor prongs, and no limitapended claims.

What is claimed is:

1. The method of producing a conductor prong for an electric connector plug of pliable material comprising cutting a longitudinal blank from a strip of. metal of the blank width, cutting a slot in from the longitudinal edge of said blank, one edge of said slot being cut at an acute angle and the v opposite edge being cut substantially at a right angle to the axis of said blank, swaging a concave socket into the blank surface adjacent the right angle edge and thereby forcing the adjacent metal stock outwardly from the longitudinal edge of said blank into an angular barb.

2. The method of producing a conductor prong for connector plugs comprising cutting a longitudinal blank from a strip of metal of the blank width, cutting a slot in from the longitudinal edge of said blank with one edge of said slot cut at an acute angle and the opposite edge at a right angle to the longitudinal axis of said blank, swaging the metal stock adjacent the right angle edge of said slot in such a manner as to cause a barb to be extruded outwardly beyond the longitudinal edge of said blank and have 0 for en electric connector plug of pliable material comprising cutting a longitudinal blank from a strip of metal of the blank width, slotting inwardly from the opposite longitudinal edges of said blank, one edge of which slots is disposed substantially at right angles to the longitudinal axis-of said blank, and forming depressed sockets in the surface of said blank adjacent said rightangle edges of said slots and thereby causing opposed barbs to be forced outwardly from the material of said blank beyond the longitudinal 4 edges.

FREDERICK R. REU'I'I'ER. 

